Composition shoe sole



Patented Feb. 19, 1946 COMPOSITION SHOE SOLE William M. Quinn, Chicopee, Mass.

No Drawing. Application November 8, 1943, Serial No. 509,502

3 Claims. (Cl. 260-727) position which may be made in large part from scrap material, thereby securing a substantial reduction in cost but without sacrifice in quality.

Other and further objects will be made apparent in the following specification and claims.

The base for my composition in its various forms is milled scrapped golf ball cover stock or its equivalent, other scrap materials which I have found useable for my purpose are refined balata residue, and cushion-cork scrap.

Scrapped golf ball covers are obtainable in substantial quantities from golf ball manufacturers who buy up old golf balls and after stripping off the old covers provide the undamaged centers with new covers. The refined balata residue is obtainable from the same source or from other manufacturers who refine balata for their products'. Because of compounding and curing processes to which the balata in scrapped golf ball covers has been subjected it has heretofor been found necessary to put the covers through an expensive reclaiming process to fit the balata content to conventional uses.

I have found that by milling, and combining the unreclaimed scrapped golf ball cover stock with other suitable ingredients, a superior leather substitute can be produced which is of particular utility when used for shoe soles and the like.

The scrapped golf ball cover stock by a simple reworking on a roll mill, is reduced to a consistency or condition in which it forms a base which I have found can be blended with various materials in varying proportions to provide shoe sole compositions of varying grades, as desired, but all possessing a toughness which gives the finished sole a characteristic ability to hold its shape and to be sewed or stitched in the same manner as leather.

As the principal filling material I prefer ground cork, preferably in the form of scrapped pieces of what is known in the trade as cushion-cork. This material com rises ground cork held together poses and the scrap pieces left after the inner soles have been blanked out can be most economically used in my composition. Other ingredients which may under various circumstances be used to advantage are relatively small amounts of refined balata, various softeners, ground cloth, wood pulp and similar filler materials. The compounding is completed by the addition of a suitable combination of curing agents for example zinc oxide with an accelerator such as that sold under the name of Tuads, and sulphur.

I have found that with the milled scrapped golf ball cover stock used as a base, substantial latitude in the selection and proportions of the other materials is permissible without substantially impairing the capacity of the composition to hold stitching which is one of the important advantages of my compositions. It is thus possible to make soles of various grades to meet various requirements as to flexibility, water resistance, durability and cost all characterized by a sewing strength substantially equivalent to that of leather.

Typical examples of compounding are as follows, the proportions being expressed by weight: (1)

Parts Scrapped golf ball covers 20.00 Scrapped cushion-cork 75.00 Refined balata 4.00 Factice Q. 2.00 Ground cloth 4.00 Zinc oxide 1.00 Sulphur .50 Tuads .10 (2) Parts Scrapped golf ball covers 20.00 Scrapped cushion-cork 40.00 Refined balata 1.00 Ground cloth 6.00 Zinc oxide .70 Sulphur .40 Tuads .07 (3) Parts Scrapped golf ball covers 20.00 Scrapped cushion-cork 35.00 Factice 1.00 Ground cloth 8.40 Zinc oxide 1.00 Sulphur .50 Tuads .15

In general a more flexible product is obtained by decreasing the amount of ground cloth and increasing the amount of cork or similar material. The ground cloth also increases the resistance to tearing, a factor of more importance in thin soles than in the thicker grades. The flexibility may further be controlled by the addition of, or by varying the amounts of, factice and refined balata.

The various ingredients are thoroughly mixed and blended on a roll mill and sheeted to the desired thickness. The sheets are then cut from the mill and cured in a platen press for from 5 to 30 minutes at about 55 pounds steam pressure.

the platens cooled and the product removed from the press. The product may be in the form of sheets from which soles and the like may be subsequently cut or the soles and the like may be' formed on the press by using suitably shaped molds.

It is sometimes advantageous from the point of view of factory operations to mill the material in two or more batches. Thus as one operation scrapped golf ball cover stock may be worked on the mill with a softener and extender such as glue to form one batch:

Parts Scrapped golf ball cover's 40.00 Glue 10.00

which may be worked in the mill at a temperature of about 165.

Further ingredients may be then added in a second milling operation:

Parts (A) 25.00 Petrolatum .50 Scrapped cushion-cork 50.00 Wood pulp 8.50

This second milling operation is preferably carried out at a slightly lower mill temperature-about 125.

A third batch is then prepared which includes curing ingredients:

Because of the presence of the curing agents the milling of batch C is carried on at a milling temperature of not over 110.

A compound may then be made up by milling together at not over 120 mill temperature:

Parts (B) 35.00 (C) 15.00

Nevinal and Laurex are trade names for commercial softeners and stabilizers respectively.

I have found that refined balata residue, that is the material left after balata has been passed through its refining operations, can to an extent be substituted for the scrapped golf ball covers. A proportion of 3 parts scrapped golf ball cover stock and 1 part refined balata residue, can for example beused in place of 4 parts of scrapped golf ball covers, to give satisfactory results for most purposes.

' While I have placed substantial emphasis on the economical advantages of the permitted use of scrap material as such, and this advantage is important in that a superior product is obtained at an exceedingly low relative cost, it will be understood that I do not exclude the use of the equivalent new materials, or equivalent scrap materials from other sources than those indicated, with the curing steps and compounding of my composition adjusted to secure a final equivalent result.

It will also be understood that my composition may if desired be cold pressed and air cured.

Since the milled scrapped golf ball cover stock forms the base for the various grades, sheets of different grade may be joined in the press to give a unified product differing in grade at different parts. Thus, thin sheets of different qualities may be superposed in the press to form a shoe sole of normal thickness having its outer portion of high wear resisting quality While the inner part may be more soft and flexible, or of cheaper quality. Similarly by properly associating pieces of the same thickness and proper shape side by side in the press, a shoe sole may be produced having the portion where the wear is greatest formed of stock compounded for wear while the surrounding portion is formed of stock compounded for flexibility, or consisting of cheaper materials.

I claim:

1. A composition sheet for shoe soles and the like, containing substantially 12% to 30% scrapped golf ball cover stock, lesser amounts of refined balata, and ground cork in excess of the scrapped golf ball cover stock.

2. A composition sheet, for shoe soles and the like, containing milled scrapped golf ball cover stock and filler materialsincluding ground cork in excess of the scrapped golf ball cover stock.

3. A composition sheet, for shoe soles and the like, containin milled scrapped golf ball cover stock and filler materials including ground cork in excess of the scrapped golf ball cover stock, factice and ground cloth.

WILLIAM M. QUINN. 

